Thursday’s tour was designed to reach out to the island community and show exactly what types of weapons will be used in the marines firing range. The weapon with the farthest reaching range and thus the largest Surface Danger Zone or SDZ is the M2 .50cal heavy machine gun. It’s a bolt fed, air cooled, machine gun with a max range of 4.22 miles. The MK19 40mm machine gun shoots 40 mm grenades up to 2,200 meters. On the range however this gun shoots inert explosives that only produce a puff of smoke. The M240G machine gun shoots 7.62mm rounds up to 2.31 miles.